Jewel setting for watches and method of making same



Sept. 13, 1927.

H. COLOMB JEWEL SETTING FOR WATCHES AND METHOD OF MAKING SAME Filed March 36. 1925 /7. Coiomb Patented Sept. 13, 1927.

UNITED STATES PATENT OFFICE.

zmmzi COLOMB, or TAVANNES, SWITZERLAND.

JEWEL SETTING FOR \VATCHES AND METHOD OF MAKING SAME.

Application filed. March as, 1925, Serial No. 18,560, and in Switzerland any is, 1924.

Heretoforejewels were fixed inside of the settings used in watch making by the following methods j (a) By enchasing, that isbyproviding within the setting a cavity with a lodging for the jewel and outside of said cavity on the side from which the jewel was introduced a concentric annular furrow leaving an annular ledge which could be chased over the jewel so as to fix it. The jewels called: a glace, a goutte and balancier have for this purpose outside forms which have become classic and are very well suited for this enchasing. l j

(b) By utilizing the elasticity of the metal of the settings and by driving the stone forcibly into a'cylindrical or slightly conical hole. In this case in order to secure the fixing of the stone it was necessary to shape these stones in a very difficult and therefore expensive way and there was always a risk of waste with certain stones and the finishing work on the settings for centering the same accordingto thehole in the stone often caused somedislocation.

WVith the method of the present invention a stone is used the profile of which at the circumferential fitting surface has a convex curved form. When the stone has. been introduced into the setting there is left on the ingress side of the hole an annular space which is filled up so as to prevent the stone from slipping back again. V

Sucha form of stone may easily be shaped andbored by special machinery with dimensions best suited for performing-the process of this invention.

v The jewel has usually two opposite, substantially flat surfaces or atleast one such substantially flat surface and a flat outer portion on its opposite surface, and these opposite surfaces are connected by anapproximately cylindrical surface. According to the present invention this circular or generally cylindrical surface is given a convex shape approximately such as would be generated by the revolution of a short are of-a circle about an axis parallel to the chord of said arc, said, axis coinciding with the axis of the central perforation or recess in the jewel which is to serve asthe journal hearing for a staff or shaft.

An embodiment of my invention and certain of the best nethods of producing the same are illustrated in the accompanying sheet of drawings in which:

Fig. l is an axial section of a jewel and a bushing therefor in position for beginning the setting process.

Fig. 2 is a similar view showing the jewel forced into the bushing.

Fig. 3 shows the finished product.

Figs. 4 and 5 are sections of modified forms of jewel prepared for use according to my invention.

Figs. 6 7 and 8 similarly illustrate a slightly modified process, and

Fig. 9 shows a further modification.

Throughout the drawingslike reference characters indicate like parts. In Figs. 1, 2 and 3, a standard form of. watch jewel called in French a glace is shown at b. The whole of the convex surface of the stone is used here as fitting surface and comes therefore into contact with the metal of the setting. This surface has a circular profile. The diameter of the middlesection of the stone is larger than the diameter of the two bases.

Preferably this shape of the circular surface m of the jewelapproximates that which would be generated by the revolution of the short are of a circle such as shown at 00 about an axis which is parallel to the chord of said are and usually coincident with the axis of the central perforation or recess 1, in said jewel. This surface might, however, be such as would be generated by the similar revolution of a short section of the perimeter of a polygon as shown in Fig. 4;, and in Fig. 5. The curvature or taper of the jewel end so produced should be slight, so that when it is forced into a bushing of brass into which it can be wedged, aslight yielding of the metalin a direction radial of the bushing will permit the complete insertion of the jewel, and this without subjecting the jewel to a degree of pressure which would crush it. For this reason the degree of taper of the jewel surface must be slight, as shown in the drawings. The metal mass in which the jewel Z is to be set is usually a small bushing a of malleable metal such as brass or copper having a central perforation, hole or recess to receive said jewel. This hole has a diam eter less than the maximum diameter of the convex surface of the jewel b but not less than the minimum diameter thereof, so that,

i when placed in the position shown in Fig. 1,

' of'a chasing tool formingja circular furrow in the bushingface as indicated at '0 in Fig. 3, or by any other suitable operation.

- Substantially the same result may be secured if the generally convex surface of the jewel consists of a series of facets such as shown at z in Fig. 4, or w in Fig. 5, instead of being of a continuously curved or globularfform. V 7 I In'eit'her case the finished pushed jewel presents the usual appearance of anenchased jewel setting shown in Fig. 3, but the jewel is held much more firmly in the bushing on account of the dovetailed relation of the convex jewel periphery and the concave surrounding surface'of the bushing metal which has'been forced inwardly against the upper portion of said jewel surface, or forced outward by pressure from the lower portion of said jewel surface.

In Figs. 6, 7 and 8 I-have illustrated a modification of the process by which a modified setting is roduced'omitting the furrow o. This is 5iown as applied to another standard form of jewel 6 called in French a goutte. In this modification the bushing a is provided with a small lip of V-shaped cross section extending upwardly around the mouth of the bore in said bushing and above the upper surface 0.: The shapes and relative proportions of the parts are otherwise the same as before. If the forcing in of the jewel is done by a plunger of a diameter large enough to overhang lip f it will force said lip down at the end of the plunger stroke and thus fill the space originally formed between it and the upper portion of the jewel as shown in Fig. 8, an intermediate stage of this operation being shown in Fig. 7. In this process the upper face of the jewelin the finished setting may be left in a'position above the plane of the upper bushing face 0 as shown in Fig. 9, which is a section of a bushing prepared for this purpose.

If it-is desired to have the conventional furrow surround the jewel in a setting produced by this modification of the process, such a furrow may be initially formed about the lip f and will then appear in the finished setting as shown at o in Fig. 9.

Of course this process could be applied to other conventional forms of jewels'than the two here illustrated, so long'as the jewel has one substantially plane surface extending at right angles to the axis of the central recess intended to form the journal bearing, and a circular exterior wall substantially concentric with said recess.

Among the advantages of the above described process may be mentioned simplicity, and ease of performance, the jewel automatically centering itself in the bore of the bushing. Also there is an automatic adjustment of final positipn of the jewel, in the processes illustratedin Figs." 1, 2; 3, 6,"? and8, the forcing plunger being automatically stopped at the right moment when it comes in contact-with the bushing face. Fractureof the jewel in the setting operation is avoided because it has alarge plane surface on which'the plunger bears evenly and the radial compression stresses to which the jewel is subjected are-also evenly distributed. i r

The advantages possessed by'the product of the process include the firmness. of bond between jewel and bushing or other metal setting, accuracy of alignment between the central recess of the jewel and the bushing bore, and accuracy of relation between jewel and bushing'plane faces. Also the simple form of bushing shown can be used, i. e. one without anyinterior ledge or other stop for fixing the position. of the jewel in the bushing, or other surrounding mass of metal in which the jewel is set. V

Having described my invention, I claim:

1. The process of-setting a jewel bearing for a rotating shaft in an encircling mass of metal which comprises the following steps: shaping a circular exterior portion of a (centrally recessed) jewel-to conform to a convex surface substantially such as would be generated by the revolution of a short arcof a circle about the axis of said jewel; preparing a mass of metal having a bore of a diameter less than the maximum.

exterior diameter of the jewel so prepared but not less than the minimum exterior diameter of said jewel; forcing said jewel into the recess in said metal mass far enough to bringadjacent fiat surfaces of the two into approximately the same plane, thereby expandinga portion of said recess to the maximum exterior diameter of said jewel and, finally, forcing the dis laced metal surrounding the said expande portion back inwardly until it closes against the adjacent convex surface of said jewel, thereby sealing the jewel in position in said metal. I r

2. A process such as defined in claim 1 in which said prepared metal mass has a short, upwardly extending lip of V-shaped cross section surrounding the mouth'of said bore at the time said-jewel is inserted therein. '3. A process such as defined in claim 1 I I (l in which said prepared metal mass has a short, upwardly extending lip of V-shaped cross section surrounding the mouth of said bore at the time said jewel is inserted therein and an annular recess in its face surounding said lip and concentric therewith.

l. The process of forming a bushed jewel bearing for use in watches and like structures, which process comprises the following steps: shaping the circular exterior portion of a centrally perforated jewel to con form to a convex surface substantially such as would be generated by the revolution of a short are of a circle about an axis parallel to the chord of said arc; preparing a bushing of malleable metal having a bore of a diameter less than the maximum exterior diameter of the jewel so prepared but not less than the minimum exterior diameter of said jewel; forcing said jewel into said bushing until adjacent surfaces of the two are in approximately the same plane; and, finally, forcing back against said jewel the metal of said bushing which has been partially displaced by the above described entrance of said jewel into the bore of said bushing.

5. The product of the herein described process, being a bushed jewel bearing composed of a centrally bored jewel having the whole of its outer rim surface substantially convex, that is to say such as would be generated by the revolution of a short are of a circle or polygon about an axis parallel to the chord of said are and coincident with the axis of said jewel perforation, whereby either portion of said jewel rim may have a slight wedging action when forced into a bushing of originally cylindrical bore of proper diameter, and a bushing of metal having a concave inner surface conforming to and pressing against said convex jewel rim surface at substantially all points thereof.

In testimony whereof I aflix my signature.

HENRI COLOMB. 

